The results of the large-scale study STRIDE-PD of patients with Parkinson's disease (PD) are presented. The aim of the study was to verify whether a combination of levodopa with DOPA decarboxylase and catechol-O-methyltransferase inhibitors (stalevo) could delay the development of dyskinesia compared to the standard two-component drug due to the more stable concentration levodopa in the blood that provided the persistent stimulation of dopamine receptors in the striatum. The results of the study allowed to discuss the issues related to PD treatment, in particular, the dose of levodopa that should not be exceeded to reduce the low risk of fluctuations and dyskinesia, and the necessity of maintaining equivalent doses of levodopa in the combination of antiparkinsonian drugs.